# NTSB DCA18CA255: Embraer ERJ175, N637CZ, Cut Bank, MT, June 17, 2018

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Data collection · Final report
- Date: June 16, 2018, 22:00 local (Jun 17, 2018, 04:00 UTC)
- Place: Cut Bank, MT
- Coordinates: 48.71389, -112.538887 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.7139&lon=-112.5389&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Turbulence encounter](https://openairdocs.org/ntsb-events/360)
- Highest injury: Serious injuries
- Injuries: 1 serious, 72 uninjured
- Status: Completed, report July 8, 2020
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- NTSB case key (mKey): 97980
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA18CA255
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97980/pdf
- Page: https://openairdocs.org/ntsb/DCA18CA255

## Probable cause

an unexpected encounter with clear air turbulence.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Turbulence: terrain induced turbulence](https://openairdocs.org/ntsb-findings/03032010): Environmental issues › Conditions/weather/phenomena · Effect on personnel; cases with it: [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/03032010/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute-cruise: Turbulence encounter](https://openairdocs.org/ntsb-events/360) (defining event); cases with it: [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md)

## Analysis

On June 16, 2018, about 2200 MDT, Compass Airlines flight 5774, N637CZ, Embraer 175, encountered turbulence while in cruise flight at flight level 300 while enroute to Calgary International Airport (CYYZ), Calgary, Alberta, Canada. Of the 73 passengers and crew onboard, one flight attendant was seriously injured. The flight was operating under 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight from Salt Lake City International Airport (KSLC), Salt Lake City, Utah to CYYZ. According to the flight crew, air traffic control (ATC) relayed pilot reports of a "smooth ride with light chop" for their route of flight. The airplane was in visual meteorological conditions and the seatbelt sign was illuminated. At the time of the turbulence encounter the aft flight attendant was finishing up beverage service and was thrown against the bulkhead and jumpseat. The flight attendant was unable to complete her duties due to the injury and two passengers assisted the flight attendant until landing. Upon arrival at the gate in CYYZ, the flight attendant was transported to the hospital where she was diagnosed with a broken vertebra.

## Factual narrative

On June 16, 2018, about 2200 MDT, Compass Airlines flight 5774, N637CZ, Embraer 175, encountered turbulence while in cruise flight at flight level 300 while enroute to Calgary International Airport (CYYZ), Calgary, Alberta, Canada. Of the 73 passengers and crew onboard, one flight attendant was seriously injured. The flight was operating under 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight from Salt Lake City International Airport (KSLC), Salt Lake City, Utah to CYYZ. According to the flight crew, air traffic control (ATC) relayed pilot reports of a "smooth ride with light chop" for their route of flight. The airplane was in visual meteorological conditions and the seatbelt sign was illuminated. At the time of the turbulence encounter the aft flight attendant was finishing up beverage service and was thrown against the bulkhead and jumpseat. The flight attendant was unable to complete her duties due to the injury and two passengers assisted the flight attendant until landing. Upon arrival at the gate in CYYZ, the flight attendant was transported to the hospital where she was diagnosed with a broken vertebra.

## Aircraft

- Registration: N637CZ (not matched to a registry record)
- Reported make and model: EMBRAER ERJ175 (200)
- Category: Airplane
- Serial number: 17000256
- Year built: 2008
- Engines: General Electric CF34-8E5 turbo fan; General Electric CF34-8E5 turbo fan
- Damage: No damage
- Flight: Part 121
- Operator: Compass Airlines, doing business as Delta Connection
- Registered owner: Delta Airlines
- Airworthiness certificate: Standard, Transport
- Departed: KSLC, Salt Lake City, UT
- Destination: CYYC, Calgary
- Flight plan: IFR
- Equipment: Data recorder, Electronic flight bag or handheld device, Electronic multifunction display, Onboard weather, Stall warning system, ADS-B, Angle of attack indicator, Auto-pilot

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review February 23, 2018; seat: left; restraint: lap only; flight hours: 3,999 total, 2,074 in this make and model, 1,917 as pilot in command, 200 in the last 90 days, 54 in the last 30 days, 0 in the last 24 hours
- Co-pilot; age 46; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review June 29, 2018; seat: right; restraint: lap only; flight hours: 2,841 total, 1,207 in this make and model, 1,561 as pilot in command, 156 in the last 90 days, 54 in the last 30 days, 0 in the last 24 hours
- Cabin crew; injuries: serious
- Cabin crew; injuries: none

## Weather

- Conditions: Night
- Turbulence: Moderate

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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